113:
571:
434:
143:
724:
578:
512:(limbs) are only known from two fragments on both left and right sides, probably belonging to the sixth (and last) pair of them. The left one had a length of 0.16 cm (0.063 in) and a width of 0.07 cm (0.028 in), while the right one was 0.27 cm (0.11 in) long and 0.06 cm (0.024 in) wide. Other
631:. As they did not usually specify the exact type locality of their material, its tracking was problematic. After studying the fossil's label and comparing it with other fossils from Mitchell's collection that had more details about their origins, it was concluded in a subsequent study that the Kelly Den
488:
plate of the head) was wide and subrectangular (almost rectangular). It was broader than long; 0.76 cm (0.30 in) wide and 0.52 cm (0.20 in) long. The details on its surface are not preserved with the exception of a
766:
was described, members of
Diploaspididae were defined as small chasmataspidids with a subrectangular or semicircular carapace, a tapering postabdomen and a short telson. Excluding the last one, which is uncertain,
627:. According to the label associated with the fossil, it was purchased in 1893 from the collection of a person surnamed Mitchell, who, along with other colleagues, was one of the fossil collectors in the area near
913:(which goes before the Devonian), extending the fossil range of the genus. This also suggests that there could be specimens from earlier times of other diploaspidids similar to
543:(dorsal half of the segments), but not the first one. The postabdomen (segments 5 to 13) also tapered posteriorly and was longer, with its 9 tergites distinguishable in the
1226:
551:(the posteriormost division of the body) is unknown, but it was probably short as in other contemporary chasmataspidids. The specimen had two cracks all over the
806:
from the rest of the chasmataspidids was the dimensions of its body, its size, the shape of its carapace and the distinctive subtrapezoidal preabdomen. Even if
392:. However, the paleontologist never formally published his findings. It would not be until 1999 when a group of three other paleontologists formally described
699:
Despite the turbulent history of the fossil, the paleontologists Jason A. Dunlop, Lyall I. Anderson and Simon J. Braddy formally proposed and described
1272:
707:
of chasmataspidid. The name suggested by
Waterston was kept to avoid future confusion. Anderson also studied a troublesome specimen allegedly at the
1213:
535:, had a total length of 1.18 cm (0.46 in). The preabdomen (segments 1 to 4) was nearly trapezoidal (that is, subtrapezoidal) and narrowed
1292:
591:
1131:"The first diploaspidid (Chelicerata: Chasmataspidida) from North America (Silurian, Bertie Group, New York State) is the oldest species of
715:. However, upon examination, it was discovered that it was not a chasmataspidid, but a poorly preserved undetermined arthropod fragment.
864:, a Scottish village near from the suspected type locality. However, the exact location from which it was recollected is still unknown.
570:
1282:
1277:
871:, just as other Devonian chasmataspidids, had its sixth pair of appendages modified into paddles. These would have made it an
648:
377:
1287:
485:
323:. Known as BMNH In 60023, it is poorly preserved and its type locality is uncertain, although it might be the Kelly Den
1117:
708:
611:
is known from one single poorly preserved specimen, BMNH In 60023. It was found in the Dundee
Formation (within the
142:
341:
was very small, only reaching 1.7 centimetres (0.67 inches) of length. It had a nearly rectangular head, with its
895:
837:
of
Scotland. It was found at the Old Red Sandstone, in the Dundee Formation. The fossil is preserved in a gray
1267:
1074:"A new chasmataspid (Chelicerata: Chasmataspida) from the Lower Devonian of the Midland Valley of Scotland"
112:
1181:
532:
662:
Charles D. Waterston borrowed the still unregistered specimen, as well as four other fossils of juvenile
516:
chasmataspidids had this pair of appendages modified into swimming "paddles", so it can be assumed that
498:
643:, could be the original site. However, this cannot be confirmed. Following the purchase, the fossil of
477:, with the size of the only known specimen estimated at only 1.7 centimetres (0.67 inches) in length.
1148:
850:
834:
297:
744:
433:
400:
223:
1139:
919:
880:
682:
three years later, where it would be labeled with the same name given by the paleontologist. Thus,
556:
536:
789:) of the specimen. The genus also resembled other Devonian chasmataspidids, but differed from the
1164:
1093:
693:
688:
137:
777:
729:
405:
1239:
1231:
723:
612:
502:
1244:
813:
s affiliation with
Diploaspididae is certain, the genus has not been included to date in any
1156:
1085:
741:
397:
304:
1106:
799:
748:
357:(the posteriormost division of the body) is not preserved, but it was probably short. The
210:
802:(spines protruding from the posterolateral corners of the carapace). What differentiated
1152:
846:
659:
624:
466:
454:
385:
320:
281:
32:
678:. However, Waterston would never publish his description, returning the fossil to the
1261:
1130:
1097:
928:
857:
509:
442:
358:
121:
70:
1168:
711:(later discovering that it was not there) which could represent another specimen of
353:
consisted of an almost trapezoidal preabdomen and a long, tapering postabdomen. The
1126:
814:
794:
505:
342:
308:
249:
1204:
555:(the head) and preabdomen, as well as dark patches probably corresponding to the
666:, to describe them. He noted the chasmataspidid nature of what would become the
524:
184:
45:
1160:
1089:
888:
790:
782:
663:
458:
197:
90:
55:
842:
838:
818:
474:
289:
174:
154:
95:
39:
547:
and with a length of approximately 0.08 cm (0.031 in) each. The
1198:
910:
786:
667:
640:
620:
616:
596:
513:
494:
490:
481:
446:
414:
346:
332:
316:
301:
126:
85:
80:
65:
60:
50:
1218:
891:
861:
752:
636:
552:
540:
528:
350:
328:
285:
100:
75:
361:, known only from a few fragments, probably had swimming paddles that
1023:
1021:
1019:
1017:
1015:
1013:
1000:
998:
996:
994:
981:
979:
977:
975:
962:
960:
958:
956:
954:
952:
950:
948:
872:
679:
652:
632:
628:
548:
544:
450:
418:
381:
366:
354:
324:
293:
164:
1175:
376:
was purchased in 1893 from a fossil collection. It was sent to the
1073:
785:
distortion (that is, a defect product of the fossilization of the
722:
704:
432:
388:
studied it and determined that it was a chasmataspidid, naming it
277:
497:
corner of the carapace, only distinguished if it is placed under
884:
853:
422:
1179:
1072:
Dunlop, Jason A.; Anderson, Lyall I.; Braddy, Simon J. (1999).
1052:
1050:
1048:
1078:
Transactions of the Royal
Society of Edinburgh: Earth Sciences
781:, although it had a longer postabdomen, perhaps because of a
539:. Vague impressions distinguish the second, third and fourth
771:
possessed these features. Regarding other chasmataspidids,
409:
and other
Devonian genera, although it is speculated that
909:, was described. Unlike the other two, this species was
696:
name that appears in an informally published document).
1107:"A summary list of fossil spiders and their relatives"
1027:
1004:
985:
966:
887:. This type of chasmataspidids subsequently invaded
1188:
883:, that is, they formed on the bottom of an ancient
1039:
1105:Dunlop, Jason A.; Penney, D.; Jekel, D. (2020).
674:, registered it as In 60023 and coined the name
655:like other fossils from Mitchell's collection.
599:, a town near where the only known specimen of
1056:
603:has been found (the exact location is unknown)
8:
875:swimmer. Furthermore, the deposits in which
345:being unknown but possibly represented by a
315:, is known from one only specimen found in
1176:
111:
22:
927:, that have yet to be discovered (i.e. a
849:of the fossil) is similar to that of the
501:. This tubercle most likely represents a
751:Chasmataspidida. It includes one single
944:
759:, from the Early Devonian of Scotland.
798:, which was much larger and had genal
845:(the physical characteristics of the
733:, a similar species of chasmataspidid
7:
703:for the first time in 1999 as a new
647:was not instantly registered in the
264:Dunlop, Anderson & Braddy, 1999
243:Dunlop, Anderson & Braddy, 1999
1028:Dunlop, Anderson & Braddy 1999
1005:Dunlop, Anderson & Braddy 1999
986:Dunlop, Anderson & Braddy 1999
967:Dunlop, Anderson & Braddy 1999
14:
833:was discovered in Early Devonian
747:, one of the two families in the
1273:Early Devonian first appearances
577:
576:
569:
141:
1040:Dunlop, Penney & Jekel 2020
453:are based on better preserved
1:
1293:Fossil taxa described in 1999
740:is classified as part of the
417:as well. It was a lacustrine
775:was considerably similar to
413:may have existed during the
384:. Decades later, in 1962, a
1118:Natural History Museum Bern
709:National Museum of Scotland
421:, meaning that it lived in
129:and only known specimen of
18:Extinct genus of arthropods
1309:
1057:Lamsdell & Briggs 2017
901:In 2017, a new species of
1283:Chasmataspidids of Europe
1161:10.1017/S0016756816000662
1090:10.1017/S0263593300007100
255:
248:
138:Scientific classification
136:
119:
110:
25:
1278:Devonian chasmataspidids
896:Late Devonian extinction
296:have been discovered in
734:
649:Natural History Museum
635:section, south of the
462:
396:. Forming part of the
378:Natural History Museum
726:
658:In 1962, the British
499:plane polarized light
436:
1125:Lamsdell, James C.;
1114:World Spider Catalog
701:Forfarella mitchelli
684:Forfarella mitchelli
676:Forfarella mitchelli
592:class=notpageimage|
403:, it was similar to
390:Forfarella mitchelli
259:Forfarella mitchelli
1288:Fossils of Scotland
1153:2017GeoM..154..175L
1140:Geological Magazine
1127:Briggs, Derek E. G.
894:, maybe due to the
867:It is thought that
563:History of research
349:in the fossil. Its
778:Diploaspis casteri
735:
730:Diploaspis casteri
689:nomen manuscriptum
520:had them as well.
463:
1255:
1254:
1240:Open Tree of Life
1182:Taxon identifiers
1120:. pp. 1β304.
613:Old Red Sandstone
531:), made up of 13
445:, details of the
327:section near the
307:. The single and
269:
268:
244:
1300:
1248:
1247:
1235:
1234:
1222:
1221:
1209:
1208:
1207:
1177:
1172:
1121:
1111:
1101:
1060:
1054:
1043:
1037:
1031:
1025:
1008:
1002:
989:
983:
970:
964:
829:The specimen of
812:
580:
579:
573:
242:
235:
222:
209:
146:
145:
115:
105:
42:
31:Temporal range:
23:
1308:
1307:
1303:
1302:
1301:
1299:
1298:
1297:
1258:
1257:
1256:
1251:
1243:
1238:
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1225:
1217:
1212:
1203:
1202:
1197:
1184:
1124:
1109:
1104:
1071:
1068:
1063:
1055:
1046:
1038:
1034:
1026:
1011:
1003:
992:
984:
973:
965:
946:
942:
937:
879:was found were
827:
810:
727:Restoration of
721:
606:
605:
604:
594:
588:
587:
586:
585:
581:
565:
467:chasmataspidids
465:Like the other
455:chasmataspidids
437:Restoration of
431:
265:
262:
241:
233:
220:
211:Chasmataspidida
207:
140:
125:drawing of the
106:
104:
103:
98:
93:
88:
83:
78:
73:
68:
63:
58:
53:
48:
38:416β393.3
37:
36:
29:
19:
12:
11:
5:
1306:
1304:
1296:
1295:
1290:
1285:
1280:
1275:
1270:
1268:Diploaspididae
1260:
1259:
1253:
1252:
1250:
1249:
1236:
1223:
1210:
1194:
1192:
1186:
1185:
1180:
1174:
1173:
1147:(1): 175β180.
1122:
1102:
1084:(3): 161β165.
1067:
1064:
1062:
1061:
1059:, p. 179.
1044:
1032:
1030:, p. 161.
1009:
1007:, p. 162.
990:
988:, p. 163.
971:
969:, p. 164.
943:
941:
938:
936:
933:
826:
823:
745:Diploaspididae
720:
719:Classification
717:
686:remained as a
660:paleontologist
625:United Kingdom
590:
589:
583:
582:
575:
574:
568:
567:
566:
564:
561:
430:
427:
401:Diploaspididae
386:paleontologist
372:The fossil of
321:United Kingdom
282:chasmataspidid
267:
266:
263:
253:
252:
246:
245:
231:
227:
226:
224:Diploaspididae
218:
214:
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205:
201:
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188:
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117:
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107:
99:
94:
89:
84:
79:
74:
69:
64:
59:
54:
49:
44:
43:
33:Early Devonian
30:
17:
13:
10:
9:
6:
4:
3:
2:
1305:
1294:
1291:
1289:
1286:
1284:
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1233:
1228:
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1195:
1193:
1191:
1187:
1183:
1178:
1170:
1166:
1162:
1158:
1154:
1150:
1146:
1142:
1141:
1136:
1134:
1128:
1123:
1119:
1115:
1108:
1103:
1099:
1095:
1091:
1087:
1083:
1079:
1075:
1070:
1069:
1065:
1058:
1053:
1051:
1049:
1045:
1042:, p. 16.
1041:
1036:
1033:
1029:
1024:
1022:
1020:
1018:
1016:
1014:
1010:
1006:
1001:
999:
997:
995:
991:
987:
982:
980:
978:
976:
972:
968:
963:
961:
959:
957:
955:
953:
951:
949:
945:
939:
934:
932:
930:
929:"ghost" range
926:
922:
921:
920:Achanarraspis
916:
912:
908:
907:D. praecursor
904:
899:
897:
893:
890:
886:
882:
878:
874:
870:
865:
863:
859:
855:
852:
848:
844:
840:
836:
832:
824:
822:
820:
816:
809:
805:
801:
797:
796:
792:
788:
784:
780:
779:
774:
770:
765:
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758:
754:
750:
746:
743:
739:
732:
731:
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714:
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706:
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634:
630:
626:
622:
618:
614:
610:
602:
598:
593:
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562:
560:
558:
557:ornamentation
554:
550:
546:
542:
538:
534:
530:
526:
521:
519:
515:
511:
507:
504:
500:
496:
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478:
476:
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435:
428:
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420:
416:
412:
408:
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399:
395:
391:
387:
383:
379:
375:
370:
368:
365:used to swim
364:
360:
356:
352:
348:
344:
340:
336:
334:
330:
326:
322:
318:
314:
310:
306:
303:
300:of the Early
299:
295:
291:
287:
284:, a group of
283:
279:
275:
274:
261:
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251:
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128:
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122:Camera lucida
118:
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109:
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97:
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87:
82:
77:
72:
67:
62:
57:
52:
47:
41:
34:
28:
24:
21:
16:
1189:
1144:
1138:
1132:
1113:
1081:
1077:
1066:Bibliography
1035:
924:
918:
914:
906:
902:
900:
876:
868:
866:
830:
828:
825:Paleoecology
817:analysis or
815:phylogenetic
807:
803:
795:Chasmataspis
793:
776:
772:
768:
763:
762:At the time
761:
757:F. mitchelli
756:
737:
736:
728:
712:
700:
698:
687:
683:
675:
671:
657:
644:
608:
607:
601:F. mitchelli
600:
595:Location of
522:
517:
493:in the left
479:
473:was a small
471:F. mitchelli
470:
464:
439:F. mitchelli
438:
410:
404:
393:
389:
373:
371:
362:
338:
337:
313:F. mitchelli
312:
309:type species
272:
271:
270:
258:
257:
250:Type species
237:
236:
191:
131:F. mitchelli
130:
120:
26:
20:
15:
664:eurypterids
537:posteriorly
525:opisthosoma
459:xiphosurans
429:Description
185:Chelicerata
181:Subphylum:
1262:Categories
1190:Forfarella
1133:Diploaspis
935:References
925:Forfarella
917:, such as
915:Diploaspis
903:Diploaspis
889:freshwater
881:lacustrine
877:Forfarella
869:Forfarella
831:Forfarella
808:Forfarella
804:Forfarella
791:Ordovician
783:taphonomic
773:Forfarella
769:Forfarella
764:Forfarella
738:Forfarella
713:Forfarella
672:Forfarella
645:Forfarella
609:Forfarella
518:Forfarella
510:appendages
443:appendages
411:Forfarella
406:Diploaspis
394:Forfarella
374:Forfarella
363:Forfarella
359:appendages
339:Forfarella
290:arthropods
273:Forfarella
238:Forfarella
198:Dekatriata
175:Arthropoda
27:Forfarella
1205:Q19842642
1098:130344322
940:Citations
856:-bearing
843:lithology
839:siltstone
819:cladogram
694:taxonomic
623:, in the
475:arthropod
319:, in the
161:Kingdom:
155:Eukaryota
1199:Wikidata
1169:85560431
1129:(2017).
911:Silurian
892:habitats
851:laminate
835:deposits
787:organism
668:holotype
641:Arbirlot
621:Scotland
617:Arbroath
597:Arbroath
584:Arbroath
541:tergites
533:segments
514:Devonian
495:anterior
491:tubercle
482:carapace
447:carapace
415:Silurian
367:actively
347:tubercle
333:Arbirlot
317:Scotland
302:Devonian
298:deposits
288:aquatic
217:Family:
171:Phylum:
165:Animalia
151:Domain:
127:holotype
1245:4721153
1232:1349327
1219:4579414
1149:Bibcode
898:event.
862:Tealing
753:species
637:village
615:) near
553:prosoma
529:abdomen
503:lateral
351:abdomen
329:village
294:Fossils
286:extinct
230:Genus:
204:Order:
1167:
1096:
873:active
841:. Its
800:spines
742:family
680:museum
653:London
633:stream
629:Forfar
549:telson
545:fossil
508:. The
486:dorsal
457:or on
451:telson
441:. The
419:animal
398:family
382:London
355:telson
325:stream
305:period
1227:IRMNG
1165:S2CID
1110:(PDF)
1094:S2CID
847:rocks
811:'
749:order
705:genus
423:lakes
278:genus
276:is a
192:Clade
1214:GBIF
885:lake
858:beds
854:fish
523:The
480:Its
449:and
343:eyes
46:Preκ
1157:doi
1145:154
1086:doi
931:).
923:or
860:in
692:(a
670:of
651:of
639:of
506:eye
380:in
331:of
280:of
1264::
1242::
1229::
1216::
1201::
1163:.
1155:.
1143:.
1137:.
1116:.
1112:.
1092:.
1082:89
1080:.
1076:.
1047:^
1012:^
993:^
974:^
947:^
905:,
821:.
755:,
619:,
559:.
469:,
425:.
369:.
335:.
311:,
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56:O
51:κ
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